A typical marine vessel has one or more internal combustion engines that drive a propulsor, such as for example a propeller, impeller, pod drive, or the like. The one or more internal combustion engines provide thrust necessary to propel the vessel.
Some marine vessels also include one or more electric motors, which are typically battery-powered motors utilized for trolling.
Abandoned U.S. patent application Ser. No. 11/505,075, expressly incorporated herein by reference, discloses marine propulsion systems that connect both an internal combustion engine and an electric motor to a propulsor in torque-transmitting relation so that the propulsor can selectively receive a sum of the torque provided by the engine and the motor. In these arrangements, a rechargeable electric storage battery unit provides current that powers the motor. The battery unit can include a single battery or a plurality of batteries. To recharge the battery unit, the motor is driven by the engine in torque transmitting relation to generate a current that is discharged to the battery unit. A computer controller commanded by a user input device is programmed to operate the system to, for example, charge the battery unit or alternately to provide electrical power from the battery unit to the motor.